Tractor-wheel



R. H. MULLER.

TRACTOR WHEEL. A APPLICATIONFILED SEPT-8, 1919.

v Patented Apr.' 5, w21.. y 3 SHEETS-SHEET l. T-1g j 4 illll R. R. MILLER.

TRACTOR WHEEL.

APPucATroN FILED SEPT. 8, 1919.

Patented Apr. 5, 1921.

3 SHEETS-SHEET 2- R. R. MILLER.

TRACTOR WHEEL.

APPLICATION FILED SEPT- 8, |9l9. ,I 933759995 Patented Apr. 5,1921.

I 3 sHEETs-sHEET s.

TES

UNITED .STA

ROYAL n. MILLER, OF CHICAGO, ILLINOIS, AssICrNon, BY MEsNn ASSIGNMENTS, 'ro MILLER TRACTION TREAD CoiIrANY, or CHICAGO, ILLINOIS, A CORPORATION or DELAWARE.

TRACTOR-WHEEL.

Patented Apr. 5, 1921.

Application filed September 8, 1919. Serial No. 322,520.v

To all fia/wm it may concern:

Be it known that I, ROYAL R. MiLLnn,-a citizen of the United States, and a resident of the city of Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Tractor-Wheels; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawings, and tov the numerals of reference vmarked thereon which form a part of this specification.-

This invention is for a tractor wheel wherein a chain tread is assembled with the wheel and is carried around by the rotation tions the chain tread has generally. been trained about, or associated with Supplementary wheels to either support, drive or maintain proper tensionv upon the chain tread. g

In the present invention the chain tread is carried upon and-by'a single wheel without the use of auxiliary means or wheels to maintain the elements in proper operative relation. Y

One of the chief objections to tractor wheels provided with chain treads and also tractor' wheels provided with tread elements pivotally connected upon the wheel so as to afford a continuous rolling surface for the wheel, is that there is a tendency for the wheel to press its way into the earth so that a hill is constantly for-ined ahead of the wheel against which the wheel must work. The true function of a tractor wheel is to move forward without slip, It has been found, however, that an element of slip is always present in the operation of tractor' wheels, which, by their construction, cause a hill to be formed in front of the wheel.

0n the other hand, a tractor wheel which moves forward withoutslip, by its nature, generally has no hill formed in 'front of its path of movement. A

The tractor wheel forming'the subject matter of my invention operates efficiently and effectively to overcome such objection. In the present inventionthe treads for the association with the wheel are pickedV up rearwardly of the wheel and led forwardly and laid flat upon the earth or road over which the wheel is moving andare inl cOmplete and full Contact with the ground 'before the weight and thrust of the tractor wheel is imposed thereon so .that there is no possibility of slippage and resultant formation of -a hill in front! of the tractor wheel. It is apparent, therefore, -that a wheel operating without slippagev is far more eliicient and will effect a greaterdrawbar pull, and as well effect a saving in lfuel of the motorvby which the wheel -on the vehicle Ais operated. Furthermore,l in view of the fact that the wheel treads are llaid in orderly succession flat upon the surface over which the wheel is'to travel prior to and engages the tread,it is obvious that no injury can result'to a1 road over which such a'tractor wheel is operated. l y

VIractor wheels which have any element -of slippage cannot butinjure a road, and

-wheelform a continuous track for move- Y ,ment and in their linked connection and the instant at which the wheel, rolls upon tinous'linked `form or of separate elements y pivoted on the-wheel, have had' the tread elements so associated with the wheel that the wheel has moved into operative relation with the tread elements prior to comi plete andV full positioning of the tread elements upon the road surface, and, of course, the great weight and thrust e'orts of a. tractor wheel upon an incompletely orim- 'properly placed f tread element, result in damage to the surface, as well as decreasing the efficiency of operation ofthe wheel.

It is an obj ect of this invention to provide-1Y a tractor wheel with a linked ltread associated therewith having a number of connected tread elements each provided with recesses forming a rack for teeth on. the tracto-r wheel,and each provided with interior rails-- to support the weight of the wheel thereon, and operated by the rotation of the wheel to forni an unbroken and smooth track surface on the ground over which the wheel rolls,

ioo` Y and from which by positive toothed engagement therewith, the wheelobtainstractive effort for forward movement.l

Itis 'also anobject .of this invention to construct a tractor wheel having associated therewith a continuous chain tread, the respective tread elements of which are provided with spaced rollers for engagement with the teeth of the tractor wheel and with the surface contacting portion of each tread element pivotally connected to the engaging' and supporting portion thereof for the tractor wheel to permit the tread surface to properly accommodate itself to the surface of the ground for angularities'between the wheel and the tread elements.

. It is furthermore an important object yof this invention to construct a tractor wheel 'true rolling movement.

It is finally an object of this invention to provide tractor wheel lstructure wherein tread elements are provided having a surface contacting portion pivotally connected to a track portion for coaction with the rim and teeth of a tractor wheel. and are linked together to forni a complete series around the tractor wheel so as to be completely supported and carried in operative relation thereby. f @ther ant further important objects of this invention will be apparent from the disclosures in the drawings speci cation.

rlhe invention (in a preferred forni) is illustrated in the drawings and hereinafter more fully described.

Drawings.

Figure 1 is an elevation of a 4tractor wheel and tread constituting my invention.

i i?. e is a srnnai i iew o,` a saga ino( i "-l t t"- ih"kth hr" t li :icc cons rucucn n eiein ne c ain Leaf. s equinlried with one additional linlr,

Fig. 3 is a. view similar to Fig. 2 showing the parte in another position. y

Fig. l is an enl view the tractor wheel shown in Fig. 1.

Fig. 5 is a detail section on line 5 5 of Fig. 6 is ay detail section on line 6-6 of 'Fig'. 1..

Fig. 7 is a view of the tread surface ofy one of the tread elements or linlrs.

Fig. 8 is aninterior vplan view of a pair f of the tread elements in linked relation.

'i Fig. 9 is a vertical longitudinal section taken through one of the tread elements.

Fig. 10 is a detail section on line 10-10 of Fig. 1. Y

Description.

T he tractor wheel as shown in Figs. 1 and l consists of a large wheel denoted as a whole by the reference numeral 1, having side anges 2 at the periphery thereof and with a series of relatively large teeth 3 arranged around the periphery centrally between the side flanges 2. That portion of the rim of the wheel 1 between the series of teeth 3 and the side flanges 2, as designated by the reference numerals 4L, is the track portion of the 1 wheel which rides upon the tracks formed by the linked tread elementshereinafter described; its shown more clearly in Figs.l 7 and 9, each of the tread elements consists of a surface contacting or treat Y plate 5, having raised ribs 6 on the surface contacting porvtion thereof which; may be of any desired coni'io'uration. and said lat-e 5 is iro'vided e P with upstanding lugs 7 extending transversely thereacross near each end theieof.

riwo track members 8k are provided foreach tread element and each of said track membei's is provided with downwardly entendey ing lugs 9, which extend transversely thereof1 andare of substantially triangular shape,A

as shown-in Fig. 10, with tlieapei: or lower endV thereof rounded off to afford a wide and smooth rounded bearing surface 10 for contact with the topsurface of the plate 5. Said one another, as shown clearly inY Figs. 9 and 10, and engaged therethrough to forni a piv-` Yotal connection between each pair short stud shafts 11. Said respective track mem-v vrespective lugs 7 andi) are registered with 100 bers 8 are connected toene another iiifparf1 allel relation said lugs 9. and shafts 12,

extending between said track members engaged yin bushings 12a.` Each .shaft has sleeves 13 thereon, and the spaces between said ,fit their ends each of the trackmembers 8 is provided with a slot 111, and a shaft 15 extends between said track elements is slidahle in bushings 16"L in the slots andpiniiedV on each shaft l5 is a sleeve` 16. The' shafts l5 afford a pivotal linked connection. between the tread elements of the structure, and the respective traclr members 8 at their ends are reduced in'thicliness, denoted by the ieference'nuineral 17, more particularly shown in at the point at which the slots 14: for said shafts l5 are provided. fis clearly shown, the portions 17at oneend of the track members are.- ilush with the inner surface of the track and aty the opposite ends, said portions 17 are flush with the outer sursleeves 13 areA engaged bythe teeth 3 ofthe tractor wheel. Yfis shown clearly in Fig. 1.

faces thereof,vso that said portions 17 of adn f jacent links are complemental with one an` other to interfit andperinit insertion of a pivotal connecting shaft 15 therebetween,

As shown clearly in Figs. 8 and 10, each of the track members 8, along its lower edge, is provided with a fiange oi rib projection 18, and similarly the flange portions 2 of the rim of the tractor wheel are recessed complementally therewith, as indicated by the reference numerals 19, to interiit with and engage said flange portions 18 when the wheel is in contact with the track members. This interfitting relation between the flanges 2 of the wheel and the flanged portions 18 of the track members servesto properly centralize dhe tread members and tractor wheel as the two move into engaging relation.

In the illustrations shown in Figs. 2 and 3, I have shown a tractor wheel having associated therewith a linked tread which has one more link'than that of the structure shown in Fig. 1, although Athe construction of the tractor wheel and each of the tread elements is identical with those described.y

ln t-he illustration shown in Fig. 1, the linked treads consist of seven tread elements, whereas the structure shown in Figs. 2 and Il utilizes eight tread elements.

Operation.

The tread for the tractor wheel is a` continuous series of tread elements in the present instance, as shown in Fig. 1, consisting of seven tread elements linked to one another b-y the shafts journaled in the bushings 16, which are slidable in the slots 14C at the ends of the tracks of the respective tread elements. The continuous tread is engaged around the tractor wheel symmetrically,.but has a greater linear length than the circumference of the tractor wheel, and is spaced therefrom on each side, only having contact with the wheel at the upper and lower portions thereof. The weight of those of the tread elementswhich are on each side and either entirely out of contact with the tractor wheel or only partially so, serves to retain the upper tread elements in engagement with `the upperportion of the tractor wheel, so that the tread cannot become accident-ally disengaged from theA tractor wheel. lf the tractor wheel is elevated by any suitable mechanism upwardly from the road surface so that the linkedrtread hangs loosely thereon, the linked tread may be readily lifted and disengaged from the tractor wheel for replacement, repair or any purpose desired. Also withdrawal and de-v tachment of any one of the shafts, or a master shaftlqwhich may be made readily removable, will serve to provide a. break inthe succession ofthe linked tread elements so that the same may be unrolled from the wheel. A. Y Y

lVith the construction shown in Fig. 1,

wherein seven tread elements are shownA each of a size bearing a certain proportion to the size of the tractor Wheel 1, first, two

of the tread elements are laid flat in contact with the road surface .for movement of the von each side thereof being at an angledrehji tion and only partially in contact with the ground.

That is to say, first two tread elements are laid in alined relation on theroad surface for movement of the tractor wheel thereover and then one only is in contact with the ground, and as' forward movement of the tractor wheel continues, again two tread elements are laid on the ground ,to form the track forthe tractor wheel. VThis operation of alternation ofthe numbers of said tread elements laid onthe ground continues. rlhe weight of the tractor wheel and its load 1s supported upon the track members 8, with the peripheral rim track surface 4: of thel tractor wheel riding upon the top surfaces yof the track members 8. The teeth 8V of the tractorwheel engage' between .the sleeve elevments v13 and 16 of the respective shafts 12 'and 15 Vmounted Aon the tread elements between the track members, thereby affording a Ypositive driving connection Vbetween the tractor wheel and the tread elements to give traction to the wheel sion thereof. f

et the slotted connection 1st betweenv adjacent tread elements, the tread elements are caused to register with one another in abut-V ting relation owing to the fact that the pivoted vshaft Yconnection V15-16 between". the said elements is forced into the eXtreme inner end of the corresponding slots 1% as the Y said element is lowered into place, as will The eviden'ced by referentel to Fig. 1. rllhe weight of the tread element first causes the for forward Yprogres-V treadv element to be supported at its lower end by the pivotedconnection engaging in the inner end of its slots 1e, and thereafter.

as the inclination ofthe treadV elements `varies fromsubstantially vertical to lowered road contact position. `the inclination thereof through this angle` and the weight f the said element will cause lthe pivot connectionfto slide. inwardly into .the inner' vend of the slots 14 of the preceding tread element. On the other hand, the shafts at the slotted connections between the tread elements which are disposed Varound the upper Y portion of the wheel are in the extremeY outer ends of the respective slots,` as shown in Fig. 1. lf, for any reason, the pivot connection between adjacent links isY not in the inner end of both of the respective slots of said links at the time the tractor wheel teeth approach the same to engage therewith, the

rounded outer ends of the tractor teeth will engage with the pivot connection and draw the same inwardly so that the same is properly disposed with reference to the stationary roller shafts in the track member to properly coact with the teeth of the tractor wheel.

In the event that a tread element in contact with the road surface should not lay flat thereon, that is horizontal with reference to its transverse axis due to irregularities Vin the road surface, the tractor wheel will nevertheless track properly thereover as the track members 8 have the pivotal connection l 1l with the tread surface so that the tread sui-tace may have an angled position, for instance, such as shownin Fig. 4L, without hindering or disturbing the proper movement of the tractor wheel thereover.

It is obvious, of course, that irregularities positive traction connection therebetween.

The tread elements will always serve eiectually to bridge irregularities in the road surface so that the tractor wheel is provided with good traction surface. It is obvious, of course, that the teeth may be disposed on the tread elements and coacting rollers provided on the wheel for positive engagement .between the wheel and tread elements.

, In the construction shown in Figs. 2 and 3, I have illustrated eight tread elements instead of seven in the continuous linked tread around the tractor wheel. The operation is Vsubstantially the same as that with seven links or tread elements, with the exception that the maximum number of tread elements which can lay in contact with a horizontal road surface is three, and the minimum number is two. as shown respectively in Figs. 2 and 3, whereas in the prior construction utilizing only seven tread elements, the minimum possible to contact a flat road surface is one and the maximum number, two.

In the latter construction utilizing eight tread elements instead of seven. it will be noted by comparison-between Fig. 1 and Figs. 2 and 3, that theftread elements do not lconform as nearly to the periphery of the wheel and as a consequence certain of the Y joints between adjacent tread elements yare not broken to the same extent as others, and .the tread elements are nearly, although not quite, in alineinent with oneanother at certain positions around the wheel. For this reason, I believe that the construction utilizing seven tread elementsproportioned in accordance with the wheel substantially as shown inFig. l is preferable, althoughboth structures operate etliciently and ina satisfactory manner. I have found that with the proportions substantially the saine as those shown between the said elements and the tractor wheel, it tlgbeA number of tread elements is increased beyond eight, certain of the joints between the tread elements disposed intermediate between the upper and departing from theV principles of this inven-` tion, and I therefore do not purpose limiting the patent granted 1 hereon otherwise than necessitated by the prior art.

Olaz'ms'. 1. A vehicle drive wheel comprising an annulus, gear teeth thereon of less width than the annulus, link tread members adapted tof be engaged by the periphery of the annulus,

means associated with the tread membersV and adapted tobe engaged between the gear teeth, and means movable relative to eachof a pair of adjacent tread members for connecting the same, whereby a true rolling re lation between the tread members and the annulus is maintained.

2. The combination with a toothed wheel Vof slotted links adapted to form a continuvous tractor tread therearound, rollers secured transversely of the links and adapted to engage the teeth on the wheel and similar rollers loosely engaged through the slots in adjacent links for connecting the same.

3. A link tractor tread for a toothed wheel f ii5k cent pairs of bars and movable relative to the bars.

. In testimony whereof I have hereunton subscribed my name in the presence of two subscribingv witnesses. Y

Y ROYAL MILLER.

Witnesses k: y

Ln BOYD. KILEY, EARL M. IIARDINE. 

